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Effect of Recycling Time on Stability of Colloidal Silica Slurry and Removal Rate in Silicon Wafer Polishing

연마 Recycling 시간에 따른 콜로이드 실리카 슬러리의 안정성 및 연마속도

  • Published : 2007.02.28

Abstract

The stability of slurry and removal rate during recycling of colloidal silica slurry was evaluated in silicon wafer polishing. The particle size distribution, pH, and zeta potential were measured to investigate the stability of colloidal silica. Large particles appeared as recycling time increased while average size of slurry did not change. Large particles were identified by EDS(energy dispersive spectrometer) as foreign substances from pad or abraded silicon flakes during polishing. As the recycling time increased, pH of slurry decreased and removal rate of silicon reduced but zeta potential decreased inversely. Hence, it could be mentioned that decrease of removal rate is related to consumption of $OH^-$ ions during recycling. Attention should be given to the control of pH of slurry during polishing.

Keywords

References

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